The compiler might not inline the trunc function call for
USE_TRUNC_BUILTIN [1].
This patch adds an optimized __trunc/__truncf for x86 used
on modf ifunc variant to avoid the trunc libcall.
Checked on x86_64, x86_64-v2, x86_64-v3, and x86_64-v4. Used -O2 and
-Os options. Performed a full make check on x86_64 with both
optimizations.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121861
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
After previous cleanups, the only code in the x86 bits/mathinline.h
that is relevant with current compilers is the inline of
__ieee754_atan2l that is conditional on __LIBC_INTERNAL_MATH_INLINES
(i.e. for when libm itself is being built).
This inline is something that does belong in glibc not GCC, since
__ieee754_atan2l is a purely internal function name. This patch moves
that inline to a new sysdeps/x86/fpu/math_private.h, removing the
bits/mathinline.h header.
Note that previously the inline was only for non-SSE 32-bit x86. That
condition does not make sense, however, for a long double function; if
it's not inlined, exactly the same x87 instruction will end up getting
used by the out-of-line function, for both 32-bit and 64-bit. So that
condition is not retained in the new version.
Tested for x86_64 and x86. As expected, installed stripped shared
libraries are unchanged for 32-bit x86, but installed stripped libm.so
is changed for x86_64 because calls to __ieee754_atan2l start being
inlined where previously they were out of line calls. (The same
change to start inlining the function would presumably also apply for
32-bit built with -mfpmath=sse, but that's not a configuration I've
tested.)
* sysdeps/x86/fpu/math_private.h: New file.
* sysdeps/x86/fpu/bits/mathinline.h: Remove.
